1mod anchor;
2pub mod locator;
3#[cfg(any(test, feature = "test-support"))]
4pub mod network;
5pub mod operation_queue;
6mod patch;
7mod point;
8mod point_utf16;
9#[cfg(any(test, feature = "test-support"))]
10pub mod random_char_iter;
11pub mod rope;
12mod selection;
13pub mod subscription;
14#[cfg(test)]
15mod tests;
16
17pub use anchor::*;
18use anyhow::Result;
19use clock::ReplicaId;
20use collections::{HashMap, HashSet};
21use locator::Locator;
22use operation_queue::OperationQueue;
23pub use patch::Patch;
24pub use point::*;
25pub use point_utf16::*;
26use postage::{barrier, oneshot, prelude::*};
27#[cfg(any(test, feature = "test-support"))]
28pub use random_char_iter::*;
29use rope::TextDimension;
30pub use rope::{Chunks, Rope, TextSummary};
31pub use selection::*;
32use std::{
33 cmp::{self, Ordering},
34 future::Future,
35 iter::Iterator,
36 ops::{self, Deref, Range, Sub},
37 str,
38 sync::Arc,
39 time::{Duration, Instant},
40};
41pub use subscription::*;
42pub use sum_tree::Bias;
43use sum_tree::{FilterCursor, SumTree};
44
45pub type TransactionId = clock::Local;
46
47pub struct Buffer {
48 snapshot: BufferSnapshot,
49 history: History,
50 deferred_ops: OperationQueue<Operation>,
51 deferred_replicas: HashSet<ReplicaId>,
52 replica_id: ReplicaId,
53 remote_id: u64,
54 local_clock: clock::Local,
55 pub lamport_clock: clock::Lamport,
56 subscriptions: Topic,
57 edit_id_resolvers: HashMap<clock::Local, Vec<oneshot::Sender<()>>>,
58 version_barriers: Vec<(clock::Global, barrier::Sender)>,
59}
60
61#[derive(Clone, Debug)]
62pub struct BufferSnapshot {
63 replica_id: ReplicaId,
64 visible_text: Rope,
65 deleted_text: Rope,
66 undo_map: UndoMap,
67 fragments: SumTree<Fragment>,
68 insertions: SumTree<InsertionFragment>,
69 pub version: clock::Global,
70}
71
72#[derive(Clone, Debug)]
73pub struct HistoryEntry {
74 transaction: Transaction,
75 first_edit_at: Instant,
76 last_edit_at: Instant,
77 suppress_grouping: bool,
78}
79
80#[derive(Clone, Debug)]
81pub struct Transaction {
82 pub id: TransactionId,
83 pub edit_ids: Vec<clock::Local>,
84 pub start: clock::Global,
85 pub end: clock::Global,
86 pub ranges: Vec<Range<FullOffset>>,
87}
88
89impl HistoryEntry {
90 pub fn transaction_id(&self) -> TransactionId {
91 self.transaction.id
92 }
93
94 fn push_edit(&mut self, edit: &EditOperation) {
95 self.transaction.edit_ids.push(edit.timestamp.local());
96 self.transaction.end.observe(edit.timestamp.local());
97
98 let mut other_ranges = edit.ranges.iter().peekable();
99 let mut new_ranges = Vec::new();
100 let insertion_len = edit.new_text.as_ref().map_or(0, |t| t.len());
101 let mut delta = 0;
102
103 for mut self_range in self.transaction.ranges.iter().cloned() {
104 self_range.start += delta;
105 self_range.end += delta;
106
107 while let Some(other_range) = other_ranges.peek() {
108 let mut other_range = (*other_range).clone();
109 other_range.start += delta;
110 other_range.end += delta;
111
112 if other_range.start <= self_range.end {
113 other_ranges.next().unwrap();
114 delta += insertion_len;
115
116 if other_range.end < self_range.start {
117 new_ranges.push(other_range.start..other_range.end + insertion_len);
118 self_range.start += insertion_len;
119 self_range.end += insertion_len;
120 } else {
121 self_range.start = cmp::min(self_range.start, other_range.start);
122 self_range.end = cmp::max(self_range.end, other_range.end) + insertion_len;
123 }
124 } else {
125 break;
126 }
127 }
128
129 new_ranges.push(self_range);
130 }
131
132 for other_range in other_ranges {
133 new_ranges.push(other_range.start + delta..other_range.end + delta + insertion_len);
134 delta += insertion_len;
135 }
136
137 self.transaction.ranges = new_ranges;
138 }
139}
140
141#[derive(Clone)]
142pub struct History {
143 // TODO: Turn this into a String or Rope, maybe.
144 pub base_text: Arc<str>,
145 operations: HashMap<clock::Local, Operation>,
146 undo_stack: Vec<HistoryEntry>,
147 redo_stack: Vec<HistoryEntry>,
148 transaction_depth: usize,
149 group_interval: Duration,
150}
151
152impl History {
153 pub fn new(base_text: Arc<str>) -> Self {
154 Self {
155 base_text,
156 operations: Default::default(),
157 undo_stack: Vec::new(),
158 redo_stack: Vec::new(),
159 transaction_depth: 0,
160 group_interval: Duration::from_millis(300),
161 }
162 }
163
164 fn push(&mut self, op: Operation) {
165 self.operations.insert(op.local_timestamp(), op);
166 }
167
168 fn start_transaction(
169 &mut self,
170 start: clock::Global,
171 now: Instant,
172 local_clock: &mut clock::Local,
173 ) -> Option<TransactionId> {
174 self.transaction_depth += 1;
175 if self.transaction_depth == 1 {
176 let id = local_clock.tick();
177 self.undo_stack.push(HistoryEntry {
178 transaction: Transaction {
179 id,
180 start: start.clone(),
181 end: start,
182 edit_ids: Default::default(),
183 ranges: Default::default(),
184 },
185 first_edit_at: now,
186 last_edit_at: now,
187 suppress_grouping: false,
188 });
189 Some(id)
190 } else {
191 None
192 }
193 }
194
195 fn end_transaction(&mut self, now: Instant) -> Option<&HistoryEntry> {
196 assert_ne!(self.transaction_depth, 0);
197 self.transaction_depth -= 1;
198 if self.transaction_depth == 0 {
199 if self
200 .undo_stack
201 .last()
202 .unwrap()
203 .transaction
204 .ranges
205 .is_empty()
206 {
207 self.undo_stack.pop();
208 None
209 } else {
210 let entry = self.undo_stack.last_mut().unwrap();
211 entry.last_edit_at = now;
212 Some(entry)
213 }
214 } else {
215 None
216 }
217 }
218
219 fn group(&mut self) -> Option<TransactionId> {
220 let mut new_len = self.undo_stack.len();
221 let mut entries = self.undo_stack.iter_mut();
222
223 if let Some(mut entry) = entries.next_back() {
224 while let Some(prev_entry) = entries.next_back() {
225 if !prev_entry.suppress_grouping
226 && entry.first_edit_at - prev_entry.last_edit_at <= self.group_interval
227 && entry.transaction.start == prev_entry.transaction.end
228 {
229 entry = prev_entry;
230 new_len -= 1;
231 } else {
232 break;
233 }
234 }
235 }
236
237 let (entries_to_keep, entries_to_merge) = self.undo_stack.split_at_mut(new_len);
238 if let Some(last_entry) = entries_to_keep.last_mut() {
239 for entry in &*entries_to_merge {
240 for edit_id in &entry.transaction.edit_ids {
241 last_entry.push_edit(self.operations[edit_id].as_edit().unwrap());
242 }
243 }
244
245 if let Some(entry) = entries_to_merge.last_mut() {
246 last_entry.last_edit_at = entry.last_edit_at;
247 last_entry.transaction.end = entry.transaction.end.clone();
248 }
249 }
250
251 self.undo_stack.truncate(new_len);
252 self.undo_stack.last().map(|e| e.transaction.id)
253 }
254
255 fn finalize_last_transaction(&mut self) -> Option<&Transaction> {
256 self.undo_stack.last_mut().map(|entry| {
257 entry.suppress_grouping = true;
258 &entry.transaction
259 })
260 }
261
262 fn push_transaction(&mut self, transaction: Transaction, now: Instant) {
263 assert_eq!(self.transaction_depth, 0);
264 self.undo_stack.push(HistoryEntry {
265 transaction,
266 first_edit_at: now,
267 last_edit_at: now,
268 suppress_grouping: false,
269 });
270 }
271
272 fn push_undo(&mut self, op_id: clock::Local) {
273 assert_ne!(self.transaction_depth, 0);
274 if let Some(Operation::Edit(edit)) = self.operations.get(&op_id) {
275 let last_transaction = self.undo_stack.last_mut().unwrap();
276 last_transaction.push_edit(&edit);
277 }
278 }
279
280 fn pop_undo(&mut self) -> Option<&HistoryEntry> {
281 assert_eq!(self.transaction_depth, 0);
282 if let Some(entry) = self.undo_stack.pop() {
283 self.redo_stack.push(entry);
284 self.redo_stack.last()
285 } else {
286 None
287 }
288 }
289
290 fn remove_from_undo(&mut self, transaction_id: TransactionId) -> &[HistoryEntry] {
291 assert_eq!(self.transaction_depth, 0);
292
293 let redo_stack_start_len = self.redo_stack.len();
294 if let Some(entry_ix) = self
295 .undo_stack
296 .iter()
297 .rposition(|entry| entry.transaction.id == transaction_id)
298 {
299 self.redo_stack
300 .extend(self.undo_stack.drain(entry_ix..).rev());
301 }
302 &self.redo_stack[redo_stack_start_len..]
303 }
304
305 fn forget(&mut self, transaction_id: TransactionId) {
306 assert_eq!(self.transaction_depth, 0);
307 if let Some(entry_ix) = self
308 .undo_stack
309 .iter()
310 .rposition(|entry| entry.transaction.id == transaction_id)
311 {
312 self.undo_stack.remove(entry_ix);
313 } else if let Some(entry_ix) = self
314 .redo_stack
315 .iter()
316 .rposition(|entry| entry.transaction.id == transaction_id)
317 {
318 self.undo_stack.remove(entry_ix);
319 }
320 }
321
322 fn pop_redo(&mut self) -> Option<&HistoryEntry> {
323 assert_eq!(self.transaction_depth, 0);
324 if let Some(entry) = self.redo_stack.pop() {
325 self.undo_stack.push(entry);
326 self.undo_stack.last()
327 } else {
328 None
329 }
330 }
331
332 fn remove_from_redo(&mut self, transaction_id: TransactionId) -> &[HistoryEntry] {
333 assert_eq!(self.transaction_depth, 0);
334
335 let undo_stack_start_len = self.undo_stack.len();
336 if let Some(entry_ix) = self
337 .redo_stack
338 .iter()
339 .rposition(|entry| entry.transaction.id == transaction_id)
340 {
341 self.undo_stack
342 .extend(self.redo_stack.drain(entry_ix..).rev());
343 }
344 &self.undo_stack[undo_stack_start_len..]
345 }
346}
347
348#[derive(Clone, Default, Debug)]
349struct UndoMap(HashMap<clock::Local, Vec<(clock::Local, u32)>>);
350
351impl UndoMap {
352 fn insert(&mut self, undo: &UndoOperation) {
353 for (edit_id, count) in &undo.counts {
354 self.0.entry(*edit_id).or_default().push((undo.id, *count));
355 }
356 }
357
358 fn is_undone(&self, edit_id: clock::Local) -> bool {
359 self.undo_count(edit_id) % 2 == 1
360 }
361
362 fn was_undone(&self, edit_id: clock::Local, version: &clock::Global) -> bool {
363 let undo_count = self
364 .0
365 .get(&edit_id)
366 .unwrap_or(&Vec::new())
367 .iter()
368 .filter(|(undo_id, _)| version.observed(*undo_id))
369 .map(|(_, undo_count)| *undo_count)
370 .max()
371 .unwrap_or(0);
372 undo_count % 2 == 1
373 }
374
375 fn undo_count(&self, edit_id: clock::Local) -> u32 {
376 self.0
377 .get(&edit_id)
378 .unwrap_or(&Vec::new())
379 .iter()
380 .map(|(_, undo_count)| *undo_count)
381 .max()
382 .unwrap_or(0)
383 }
384}
385
386struct Edits<'a, D: TextDimension, F: FnMut(&FragmentSummary) -> bool> {
387 visible_cursor: rope::Cursor<'a>,
388 deleted_cursor: rope::Cursor<'a>,
389 fragments_cursor: Option<FilterCursor<'a, F, Fragment, FragmentTextSummary>>,
390 undos: &'a UndoMap,
391 since: &'a clock::Global,
392 old_end: D,
393 new_end: D,
394 range: Range<(&'a Locator, usize)>,
395}
396
397#[derive(Clone, Debug, Default, Eq, PartialEq)]
398pub struct Edit<D> {
399 pub old: Range<D>,
400 pub new: Range<D>,
401}
402
403impl<D> Edit<D>
404where
405 D: Sub<D, Output = D> + PartialEq + Copy,
406{
407 pub fn old_len(&self) -> D {
408 self.old.end - self.old.start
409 }
410
411 pub fn new_len(&self) -> D {
412 self.new.end - self.new.start
413 }
414
415 pub fn is_empty(&self) -> bool {
416 self.old.start == self.old.end && self.new.start == self.new.end
417 }
418}
419
420impl<D1, D2> Edit<(D1, D2)> {
421 pub fn flatten(self) -> (Edit<D1>, Edit<D2>) {
422 (
423 Edit {
424 old: self.old.start.0..self.old.end.0,
425 new: self.new.start.0..self.new.end.0,
426 },
427 Edit {
428 old: self.old.start.1..self.old.end.1,
429 new: self.new.start.1..self.new.end.1,
430 },
431 )
432 }
433}
434
435#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord)]
436pub struct InsertionTimestamp {
437 pub replica_id: ReplicaId,
438 pub local: clock::Seq,
439 pub lamport: clock::Seq,
440}
441
442impl InsertionTimestamp {
443 pub fn local(&self) -> clock::Local {
444 clock::Local {
445 replica_id: self.replica_id,
446 value: self.local,
447 }
448 }
449
450 pub fn lamport(&self) -> clock::Lamport {
451 clock::Lamport {
452 replica_id: self.replica_id,
453 value: self.lamport,
454 }
455 }
456}
457
458#[derive(Eq, PartialEq, Clone, Debug)]
459pub struct Fragment {
460 pub id: Locator,
461 pub insertion_timestamp: InsertionTimestamp,
462 pub insertion_offset: usize,
463 pub len: usize,
464 pub visible: bool,
465 pub deletions: HashSet<clock::Local>,
466 pub max_undos: clock::Global,
467}
468
469#[derive(Eq, PartialEq, Clone, Debug)]
470pub struct FragmentSummary {
471 text: FragmentTextSummary,
472 max_id: Locator,
473 max_version: clock::Global,
474 min_insertion_version: clock::Global,
475 max_insertion_version: clock::Global,
476}
477
478#[derive(Copy, Default, Clone, Debug, PartialEq, Eq)]
479struct FragmentTextSummary {
480 visible: usize,
481 deleted: usize,
482}
483
484impl<'a> sum_tree::Dimension<'a, FragmentSummary> for FragmentTextSummary {
485 fn add_summary(&mut self, summary: &'a FragmentSummary, _: &Option<clock::Global>) {
486 self.visible += summary.text.visible;
487 self.deleted += summary.text.deleted;
488 }
489}
490
491#[derive(Eq, PartialEq, Clone, Debug)]
492struct InsertionFragment {
493 timestamp: clock::Local,
494 split_offset: usize,
495 fragment_id: Locator,
496}
497
498#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
499struct InsertionFragmentKey {
500 timestamp: clock::Local,
501 split_offset: usize,
502}
503
504#[derive(Clone, Debug, Eq, PartialEq)]
505pub enum Operation {
506 Edit(EditOperation),
507 Undo {
508 undo: UndoOperation,
509 lamport_timestamp: clock::Lamport,
510 },
511}
512
513#[derive(Clone, Debug, Eq, PartialEq)]
514pub struct EditOperation {
515 pub timestamp: InsertionTimestamp,
516 pub version: clock::Global,
517 pub ranges: Vec<Range<FullOffset>>,
518 pub new_text: Option<String>,
519}
520
521#[derive(Clone, Debug, Eq, PartialEq)]
522pub struct UndoOperation {
523 pub id: clock::Local,
524 pub counts: HashMap<clock::Local, u32>,
525 pub transaction_ranges: Vec<Range<FullOffset>>,
526 pub transaction_version: clock::Global,
527 pub version: clock::Global,
528}
529
530impl Buffer {
531 pub fn new(replica_id: u16, remote_id: u64, history: History) -> Buffer {
532 let mut fragments = SumTree::new();
533 let mut insertions = SumTree::new();
534
535 let mut local_clock = clock::Local::new(replica_id);
536 let mut lamport_clock = clock::Lamport::new(replica_id);
537 let mut version = clock::Global::new();
538 let visible_text = Rope::from(history.base_text.as_ref());
539 if visible_text.len() > 0 {
540 let insertion_timestamp = InsertionTimestamp {
541 replica_id: 0,
542 local: 1,
543 lamport: 1,
544 };
545 local_clock.observe(insertion_timestamp.local());
546 lamport_clock.observe(insertion_timestamp.lamport());
547 version.observe(insertion_timestamp.local());
548 let fragment_id = Locator::between(&Locator::min(), &Locator::max());
549 let fragment = Fragment {
550 id: fragment_id,
551 insertion_timestamp,
552 insertion_offset: 0,
553 len: visible_text.len(),
554 visible: true,
555 deletions: Default::default(),
556 max_undos: Default::default(),
557 };
558 insertions.push(InsertionFragment::new(&fragment), &());
559 fragments.push(fragment, &None);
560 }
561
562 Buffer {
563 snapshot: BufferSnapshot {
564 replica_id,
565 visible_text,
566 deleted_text: Rope::new(),
567 fragments,
568 insertions,
569 version,
570 undo_map: Default::default(),
571 },
572 history,
573 deferred_ops: OperationQueue::new(),
574 deferred_replicas: HashSet::default(),
575 replica_id,
576 remote_id,
577 local_clock,
578 lamport_clock,
579 subscriptions: Default::default(),
580 edit_id_resolvers: Default::default(),
581 version_barriers: Default::default(),
582 }
583 }
584
585 pub fn version(&self) -> clock::Global {
586 self.version.clone()
587 }
588
589 pub fn snapshot(&self) -> BufferSnapshot {
590 self.snapshot.clone()
591 }
592
593 pub fn replica_id(&self) -> ReplicaId {
594 self.local_clock.replica_id
595 }
596
597 pub fn remote_id(&self) -> u64 {
598 self.remote_id
599 }
600
601 pub fn deferred_ops_len(&self) -> usize {
602 self.deferred_ops.len()
603 }
604
605 pub fn transaction_group_interval(&self) -> Duration {
606 self.history.group_interval
607 }
608
609 pub fn edit<R, I, S, T>(&mut self, ranges: R, new_text: T) -> Operation
610 where
611 R: IntoIterator<IntoIter = I>,
612 I: ExactSizeIterator<Item = Range<S>>,
613 S: ToOffset,
614 T: Into<String>,
615 {
616 let new_text = new_text.into();
617 let new_text_len = new_text.len();
618 let new_text = if new_text_len > 0 {
619 Some(new_text)
620 } else {
621 None
622 };
623
624 self.start_transaction();
625 let timestamp = InsertionTimestamp {
626 replica_id: self.replica_id,
627 local: self.local_clock.tick().value,
628 lamport: self.lamport_clock.tick().value,
629 };
630 let operation =
631 Operation::Edit(self.apply_local_edit(ranges.into_iter(), new_text, timestamp));
632
633 self.history.push(operation.clone());
634 self.history.push_undo(operation.local_timestamp());
635 self.snapshot.version.observe(operation.local_timestamp());
636 self.end_transaction();
637 operation
638 }
639
640 fn apply_local_edit<S: ToOffset>(
641 &mut self,
642 ranges: impl ExactSizeIterator<Item = Range<S>>,
643 new_text: Option<String>,
644 timestamp: InsertionTimestamp,
645 ) -> EditOperation {
646 let mut edits = Patch::default();
647 let mut edit_op = EditOperation {
648 timestamp,
649 version: self.version(),
650 ranges: Vec::with_capacity(ranges.len()),
651 new_text: None,
652 };
653 let mut new_insertions = Vec::new();
654 let mut insertion_offset = 0;
655
656 let mut ranges = ranges
657 .map(|range| range.start.to_offset(&*self)..range.end.to_offset(&*self))
658 .peekable();
659
660 let mut new_ropes =
661 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
662 let mut old_fragments = self.fragments.cursor::<FragmentTextSummary>();
663 let mut new_fragments =
664 old_fragments.slice(&ranges.peek().unwrap().start, Bias::Right, &None);
665 new_ropes.push_tree(new_fragments.summary().text);
666
667 let mut fragment_start = old_fragments.start().visible;
668 for range in ranges {
669 let fragment_end = old_fragments.end(&None).visible;
670
671 // If the current fragment ends before this range, then jump ahead to the first fragment
672 // that extends past the start of this range, reusing any intervening fragments.
673 if fragment_end < range.start {
674 // If the current fragment has been partially consumed, then consume the rest of it
675 // and advance to the next fragment before slicing.
676 if fragment_start > old_fragments.start().visible {
677 if fragment_end > fragment_start {
678 let mut suffix = old_fragments.item().unwrap().clone();
679 suffix.len = fragment_end - fragment_start;
680 suffix.insertion_offset += fragment_start - old_fragments.start().visible;
681 new_insertions.push(InsertionFragment::insert_new(&suffix));
682 new_ropes.push_fragment(&suffix, suffix.visible);
683 new_fragments.push(suffix, &None);
684 }
685 old_fragments.next(&None);
686 }
687
688 let slice = old_fragments.slice(&range.start, Bias::Right, &None);
689 new_ropes.push_tree(slice.summary().text);
690 new_fragments.push_tree(slice, &None);
691 fragment_start = old_fragments.start().visible;
692 }
693
694 let full_range_start = FullOffset(range.start + old_fragments.start().deleted);
695
696 // Preserve any portion of the current fragment that precedes this range.
697 if fragment_start < range.start {
698 let mut prefix = old_fragments.item().unwrap().clone();
699 prefix.len = range.start - fragment_start;
700 prefix.insertion_offset += fragment_start - old_fragments.start().visible;
701 prefix.id = Locator::between(&new_fragments.summary().max_id, &prefix.id);
702 new_insertions.push(InsertionFragment::insert_new(&prefix));
703 new_ropes.push_fragment(&prefix, prefix.visible);
704 new_fragments.push(prefix, &None);
705 fragment_start = range.start;
706 }
707
708 // Insert the new text before any existing fragments within the range.
709 if let Some(new_text) = new_text.as_deref() {
710 let new_start = new_fragments.summary().text.visible;
711 edits.push(Edit {
712 old: fragment_start..fragment_start,
713 new: new_start..new_start + new_text.len(),
714 });
715 let fragment = Fragment {
716 id: Locator::between(
717 &new_fragments.summary().max_id,
718 old_fragments
719 .item()
720 .map_or(&Locator::max(), |old_fragment| &old_fragment.id),
721 ),
722 insertion_timestamp: timestamp,
723 insertion_offset,
724 len: new_text.len(),
725 deletions: Default::default(),
726 max_undos: Default::default(),
727 visible: true,
728 };
729 new_insertions.push(InsertionFragment::insert_new(&fragment));
730 new_ropes.push_str(new_text);
731 new_fragments.push(fragment, &None);
732 insertion_offset += new_text.len();
733 }
734
735 // Advance through every fragment that intersects this range, marking the intersecting
736 // portions as deleted.
737 while fragment_start < range.end {
738 let fragment = old_fragments.item().unwrap();
739 let fragment_end = old_fragments.end(&None).visible;
740 let mut intersection = fragment.clone();
741 let intersection_end = cmp::min(range.end, fragment_end);
742 if fragment.visible {
743 intersection.len = intersection_end - fragment_start;
744 intersection.insertion_offset += fragment_start - old_fragments.start().visible;
745 intersection.id =
746 Locator::between(&new_fragments.summary().max_id, &intersection.id);
747 intersection.deletions.insert(timestamp.local());
748 intersection.visible = false;
749 }
750 if intersection.len > 0 {
751 if fragment.visible && !intersection.visible {
752 let new_start = new_fragments.summary().text.visible;
753 edits.push(Edit {
754 old: fragment_start..intersection_end,
755 new: new_start..new_start,
756 });
757 }
758 new_insertions.push(InsertionFragment::insert_new(&intersection));
759 new_ropes.push_fragment(&intersection, fragment.visible);
760 new_fragments.push(intersection, &None);
761 fragment_start = intersection_end;
762 }
763 if fragment_end <= range.end {
764 old_fragments.next(&None);
765 }
766 }
767
768 let full_range_end = FullOffset(range.end + old_fragments.start().deleted);
769 edit_op.ranges.push(full_range_start..full_range_end);
770 }
771
772 // If the current fragment has been partially consumed, then consume the rest of it
773 // and advance to the next fragment before slicing.
774 if fragment_start > old_fragments.start().visible {
775 let fragment_end = old_fragments.end(&None).visible;
776 if fragment_end > fragment_start {
777 let mut suffix = old_fragments.item().unwrap().clone();
778 suffix.len = fragment_end - fragment_start;
779 suffix.insertion_offset += fragment_start - old_fragments.start().visible;
780 new_insertions.push(InsertionFragment::insert_new(&suffix));
781 new_ropes.push_fragment(&suffix, suffix.visible);
782 new_fragments.push(suffix, &None);
783 }
784 old_fragments.next(&None);
785 }
786
787 let suffix = old_fragments.suffix(&None);
788 new_ropes.push_tree(suffix.summary().text);
789 new_fragments.push_tree(suffix, &None);
790 let (visible_text, deleted_text) = new_ropes.finish();
791 drop(old_fragments);
792
793 self.snapshot.fragments = new_fragments;
794 self.snapshot.insertions.edit(new_insertions, &());
795 self.snapshot.visible_text = visible_text;
796 self.snapshot.deleted_text = deleted_text;
797 self.subscriptions.publish_mut(&edits);
798 edit_op.new_text = new_text;
799 edit_op
800 }
801
802 pub fn apply_ops<I: IntoIterator<Item = Operation>>(&mut self, ops: I) -> Result<()> {
803 let mut deferred_ops = Vec::new();
804 for op in ops {
805 self.history.push(op.clone());
806 if self.can_apply_op(&op) {
807 self.apply_op(op)?;
808 } else {
809 self.deferred_replicas.insert(op.replica_id());
810 deferred_ops.push(op);
811 }
812 }
813 self.deferred_ops.insert(deferred_ops);
814 self.flush_deferred_ops()?;
815 Ok(())
816 }
817
818 fn apply_op(&mut self, op: Operation) -> Result<()> {
819 match op {
820 Operation::Edit(edit) => {
821 if !self.version.observed(edit.timestamp.local()) {
822 self.apply_remote_edit(
823 &edit.version,
824 &edit.ranges,
825 edit.new_text.as_deref(),
826 edit.timestamp,
827 );
828 self.snapshot.version.observe(edit.timestamp.local());
829 self.resolve_edit(edit.timestamp.local());
830 }
831 }
832 Operation::Undo {
833 undo,
834 lamport_timestamp,
835 } => {
836 if !self.version.observed(undo.id) {
837 self.apply_undo(&undo)?;
838 self.snapshot.version.observe(undo.id);
839 self.lamport_clock.observe(lamport_timestamp);
840 }
841 }
842 }
843 self.version_barriers
844 .retain(|(version, _)| !self.snapshot.version().observed_all(version));
845 Ok(())
846 }
847
848 fn apply_remote_edit(
849 &mut self,
850 version: &clock::Global,
851 ranges: &[Range<FullOffset>],
852 new_text: Option<&str>,
853 timestamp: InsertionTimestamp,
854 ) {
855 if ranges.is_empty() {
856 return;
857 }
858
859 let mut edits = Patch::default();
860 let cx = Some(version.clone());
861 let mut new_insertions = Vec::new();
862 let mut insertion_offset = 0;
863 let mut new_ropes =
864 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
865 let mut old_fragments = self.fragments.cursor::<(VersionedFullOffset, usize)>();
866 let mut new_fragments = old_fragments.slice(
867 &VersionedFullOffset::Offset(ranges[0].start),
868 Bias::Left,
869 &cx,
870 );
871 new_ropes.push_tree(new_fragments.summary().text);
872
873 let mut fragment_start = old_fragments.start().0.full_offset();
874 for range in ranges {
875 let fragment_end = old_fragments.end(&cx).0.full_offset();
876
877 // If the current fragment ends before this range, then jump ahead to the first fragment
878 // that extends past the start of this range, reusing any intervening fragments.
879 if fragment_end < range.start {
880 // If the current fragment has been partially consumed, then consume the rest of it
881 // and advance to the next fragment before slicing.
882 if fragment_start > old_fragments.start().0.full_offset() {
883 if fragment_end > fragment_start {
884 let mut suffix = old_fragments.item().unwrap().clone();
885 suffix.len = fragment_end.0 - fragment_start.0;
886 suffix.insertion_offset +=
887 fragment_start - old_fragments.start().0.full_offset();
888 new_insertions.push(InsertionFragment::insert_new(&suffix));
889 new_ropes.push_fragment(&suffix, suffix.visible);
890 new_fragments.push(suffix, &None);
891 }
892 old_fragments.next(&cx);
893 }
894
895 let slice =
896 old_fragments.slice(&VersionedFullOffset::Offset(range.start), Bias::Left, &cx);
897 new_ropes.push_tree(slice.summary().text);
898 new_fragments.push_tree(slice, &None);
899 fragment_start = old_fragments.start().0.full_offset();
900 }
901
902 // If we are at the end of a non-concurrent fragment, advance to the next one.
903 let fragment_end = old_fragments.end(&cx).0.full_offset();
904 if fragment_end == range.start && fragment_end > fragment_start {
905 let mut fragment = old_fragments.item().unwrap().clone();
906 fragment.len = fragment_end.0 - fragment_start.0;
907 fragment.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
908 new_insertions.push(InsertionFragment::insert_new(&fragment));
909 new_ropes.push_fragment(&fragment, fragment.visible);
910 new_fragments.push(fragment, &None);
911 old_fragments.next(&cx);
912 fragment_start = old_fragments.start().0.full_offset();
913 }
914
915 // Skip over insertions that are concurrent to this edit, but have a lower lamport
916 // timestamp.
917 while let Some(fragment) = old_fragments.item() {
918 if fragment_start == range.start
919 && fragment.insertion_timestamp.lamport() > timestamp.lamport()
920 {
921 new_ropes.push_fragment(fragment, fragment.visible);
922 new_fragments.push(fragment.clone(), &None);
923 old_fragments.next(&cx);
924 debug_assert_eq!(fragment_start, range.start);
925 } else {
926 break;
927 }
928 }
929 debug_assert!(fragment_start <= range.start);
930
931 // Preserve any portion of the current fragment that precedes this range.
932 if fragment_start < range.start {
933 let mut prefix = old_fragments.item().unwrap().clone();
934 prefix.len = range.start.0 - fragment_start.0;
935 prefix.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
936 prefix.id = Locator::between(&new_fragments.summary().max_id, &prefix.id);
937 new_insertions.push(InsertionFragment::insert_new(&prefix));
938 fragment_start = range.start;
939 new_ropes.push_fragment(&prefix, prefix.visible);
940 new_fragments.push(prefix, &None);
941 }
942
943 // Insert the new text before any existing fragments within the range.
944 if let Some(new_text) = new_text {
945 let mut old_start = old_fragments.start().1;
946 if old_fragments.item().map_or(false, |f| f.visible) {
947 old_start += fragment_start.0 - old_fragments.start().0.full_offset().0;
948 }
949 let new_start = new_fragments.summary().text.visible;
950 edits.push(Edit {
951 old: old_start..old_start,
952 new: new_start..new_start + new_text.len(),
953 });
954 let fragment = Fragment {
955 id: Locator::between(
956 &new_fragments.summary().max_id,
957 old_fragments
958 .item()
959 .map_or(&Locator::max(), |old_fragment| &old_fragment.id),
960 ),
961 insertion_timestamp: timestamp,
962 insertion_offset,
963 len: new_text.len(),
964 deletions: Default::default(),
965 max_undos: Default::default(),
966 visible: true,
967 };
968 new_insertions.push(InsertionFragment::insert_new(&fragment));
969 new_ropes.push_str(new_text);
970 new_fragments.push(fragment, &None);
971 insertion_offset += new_text.len();
972 }
973
974 // Advance through every fragment that intersects this range, marking the intersecting
975 // portions as deleted.
976 while fragment_start < range.end {
977 let fragment = old_fragments.item().unwrap();
978 let fragment_end = old_fragments.end(&cx).0.full_offset();
979 let mut intersection = fragment.clone();
980 let intersection_end = cmp::min(range.end, fragment_end);
981 if fragment.was_visible(version, &self.undo_map) {
982 intersection.len = intersection_end.0 - fragment_start.0;
983 intersection.insertion_offset +=
984 fragment_start - old_fragments.start().0.full_offset();
985 intersection.id =
986 Locator::between(&new_fragments.summary().max_id, &intersection.id);
987 intersection.deletions.insert(timestamp.local());
988 intersection.visible = false;
989 }
990 if intersection.len > 0 {
991 if fragment.visible && !intersection.visible {
992 let old_start = old_fragments.start().1
993 + (fragment_start.0 - old_fragments.start().0.full_offset().0);
994 let new_start = new_fragments.summary().text.visible;
995 edits.push(Edit {
996 old: old_start..old_start + intersection.len,
997 new: new_start..new_start,
998 });
999 }
1000 new_insertions.push(InsertionFragment::insert_new(&intersection));
1001 new_ropes.push_fragment(&intersection, fragment.visible);
1002 new_fragments.push(intersection, &None);
1003 fragment_start = intersection_end;
1004 }
1005 if fragment_end <= range.end {
1006 old_fragments.next(&cx);
1007 }
1008 }
1009 }
1010
1011 // If the current fragment has been partially consumed, then consume the rest of it
1012 // and advance to the next fragment before slicing.
1013 if fragment_start > old_fragments.start().0.full_offset() {
1014 let fragment_end = old_fragments.end(&cx).0.full_offset();
1015 if fragment_end > fragment_start {
1016 let mut suffix = old_fragments.item().unwrap().clone();
1017 suffix.len = fragment_end.0 - fragment_start.0;
1018 suffix.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
1019 new_insertions.push(InsertionFragment::insert_new(&suffix));
1020 new_ropes.push_fragment(&suffix, suffix.visible);
1021 new_fragments.push(suffix, &None);
1022 }
1023 old_fragments.next(&cx);
1024 }
1025
1026 let suffix = old_fragments.suffix(&cx);
1027 new_ropes.push_tree(suffix.summary().text);
1028 new_fragments.push_tree(suffix, &None);
1029 let (visible_text, deleted_text) = new_ropes.finish();
1030 drop(old_fragments);
1031
1032 self.snapshot.fragments = new_fragments;
1033 self.snapshot.visible_text = visible_text;
1034 self.snapshot.deleted_text = deleted_text;
1035 self.snapshot.insertions.edit(new_insertions, &());
1036 self.local_clock.observe(timestamp.local());
1037 self.lamport_clock.observe(timestamp.lamport());
1038 self.subscriptions.publish_mut(&edits);
1039 }
1040
1041 fn apply_undo(&mut self, undo: &UndoOperation) -> Result<()> {
1042 let mut edits = Patch::default();
1043 self.snapshot.undo_map.insert(undo);
1044
1045 let mut cx = undo.transaction_version.clone();
1046 for edit_id in undo.counts.keys().copied() {
1047 cx.observe(edit_id);
1048 }
1049 let cx = Some(cx);
1050
1051 let mut old_fragments = self.fragments.cursor::<(VersionedFullOffset, usize)>();
1052 let mut new_fragments = old_fragments.slice(
1053 &VersionedFullOffset::Offset(undo.transaction_ranges[0].start),
1054 Bias::Right,
1055 &cx,
1056 );
1057 let mut new_ropes =
1058 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
1059 new_ropes.push_tree(new_fragments.summary().text);
1060
1061 for range in &undo.transaction_ranges {
1062 let mut end_offset = old_fragments.end(&cx).0.full_offset();
1063
1064 if end_offset < range.start {
1065 let preceding_fragments = old_fragments.slice(
1066 &VersionedFullOffset::Offset(range.start),
1067 Bias::Right,
1068 &cx,
1069 );
1070 new_ropes.push_tree(preceding_fragments.summary().text);
1071 new_fragments.push_tree(preceding_fragments, &None);
1072 }
1073
1074 while end_offset <= range.end {
1075 if let Some(fragment) = old_fragments.item() {
1076 let mut fragment = fragment.clone();
1077 let fragment_was_visible = fragment.visible;
1078
1079 if fragment.was_visible(&undo.transaction_version, &self.undo_map)
1080 || undo
1081 .counts
1082 .contains_key(&fragment.insertion_timestamp.local())
1083 {
1084 fragment.visible = fragment.is_visible(&self.undo_map);
1085 fragment.max_undos.observe(undo.id);
1086 }
1087
1088 let old_start = old_fragments.start().1;
1089 let new_start = new_fragments.summary().text.visible;
1090 if fragment_was_visible && !fragment.visible {
1091 edits.push(Edit {
1092 old: old_start..old_start + fragment.len,
1093 new: new_start..new_start,
1094 });
1095 } else if !fragment_was_visible && fragment.visible {
1096 edits.push(Edit {
1097 old: old_start..old_start,
1098 new: new_start..new_start + fragment.len,
1099 });
1100 }
1101 new_ropes.push_fragment(&fragment, fragment_was_visible);
1102 new_fragments.push(fragment, &None);
1103
1104 old_fragments.next(&cx);
1105 if end_offset == old_fragments.end(&cx).0.full_offset() {
1106 let unseen_fragments = old_fragments.slice(
1107 &VersionedFullOffset::Offset(end_offset),
1108 Bias::Right,
1109 &cx,
1110 );
1111 new_ropes.push_tree(unseen_fragments.summary().text);
1112 new_fragments.push_tree(unseen_fragments, &None);
1113 }
1114 end_offset = old_fragments.end(&cx).0.full_offset();
1115 } else {
1116 break;
1117 }
1118 }
1119 }
1120
1121 let suffix = old_fragments.suffix(&cx);
1122 new_ropes.push_tree(suffix.summary().text);
1123 new_fragments.push_tree(suffix, &None);
1124
1125 drop(old_fragments);
1126 let (visible_text, deleted_text) = new_ropes.finish();
1127 self.snapshot.fragments = new_fragments;
1128 self.snapshot.visible_text = visible_text;
1129 self.snapshot.deleted_text = deleted_text;
1130 self.subscriptions.publish_mut(&edits);
1131 Ok(())
1132 }
1133
1134 fn flush_deferred_ops(&mut self) -> Result<()> {
1135 self.deferred_replicas.clear();
1136 let mut deferred_ops = Vec::new();
1137 for op in self.deferred_ops.drain().iter().cloned() {
1138 if self.can_apply_op(&op) {
1139 self.apply_op(op)?;
1140 } else {
1141 self.deferred_replicas.insert(op.replica_id());
1142 deferred_ops.push(op);
1143 }
1144 }
1145 self.deferred_ops.insert(deferred_ops);
1146 Ok(())
1147 }
1148
1149 fn can_apply_op(&self, op: &Operation) -> bool {
1150 if self.deferred_replicas.contains(&op.replica_id()) {
1151 false
1152 } else {
1153 match op {
1154 Operation::Edit(edit) => self.version.observed_all(&edit.version),
1155 Operation::Undo { undo, .. } => self.version.observed_all(&undo.version),
1156 }
1157 }
1158 }
1159
1160 pub fn peek_undo_stack(&self) -> Option<&HistoryEntry> {
1161 self.history.undo_stack.last()
1162 }
1163
1164 pub fn peek_redo_stack(&self) -> Option<&HistoryEntry> {
1165 self.history.redo_stack.last()
1166 }
1167
1168 pub fn start_transaction(&mut self) -> Option<TransactionId> {
1169 self.start_transaction_at(Instant::now())
1170 }
1171
1172 pub fn start_transaction_at(&mut self, now: Instant) -> Option<TransactionId> {
1173 self.history
1174 .start_transaction(self.version.clone(), now, &mut self.local_clock)
1175 }
1176
1177 pub fn end_transaction(&mut self) -> Option<(TransactionId, clock::Global)> {
1178 self.end_transaction_at(Instant::now())
1179 }
1180
1181 pub fn end_transaction_at(&mut self, now: Instant) -> Option<(TransactionId, clock::Global)> {
1182 if let Some(entry) = self.history.end_transaction(now) {
1183 let since = entry.transaction.start.clone();
1184 let id = self.history.group().unwrap();
1185 Some((id, since))
1186 } else {
1187 None
1188 }
1189 }
1190
1191 pub fn finalize_last_transaction(&mut self) -> Option<&Transaction> {
1192 self.history.finalize_last_transaction()
1193 }
1194
1195 pub fn base_text(&self) -> &Arc<str> {
1196 &self.history.base_text
1197 }
1198
1199 pub fn history(&self) -> impl Iterator<Item = &Operation> {
1200 self.history.operations.values()
1201 }
1202
1203 pub fn undo_history(&self) -> impl Iterator<Item = (&clock::Local, &[(clock::Local, u32)])> {
1204 self.undo_map
1205 .0
1206 .iter()
1207 .map(|(edit_id, undo_counts)| (edit_id, undo_counts.as_slice()))
1208 }
1209
1210 pub fn undo(&mut self) -> Option<(TransactionId, Operation)> {
1211 if let Some(entry) = self.history.pop_undo() {
1212 let transaction = entry.transaction.clone();
1213 let transaction_id = transaction.id;
1214 let op = self.undo_or_redo(transaction).unwrap();
1215 Some((transaction_id, op))
1216 } else {
1217 None
1218 }
1219 }
1220
1221 pub fn undo_to_transaction(&mut self, transaction_id: TransactionId) -> Vec<Operation> {
1222 let transactions = self
1223 .history
1224 .remove_from_undo(transaction_id)
1225 .iter()
1226 .map(|entry| entry.transaction.clone())
1227 .collect::<Vec<_>>();
1228 transactions
1229 .into_iter()
1230 .map(|transaction| self.undo_or_redo(transaction).unwrap())
1231 .collect()
1232 }
1233
1234 pub fn forget_transaction(&mut self, transaction_id: TransactionId) {
1235 self.history.forget(transaction_id);
1236 }
1237
1238 pub fn redo(&mut self) -> Option<(TransactionId, Operation)> {
1239 if let Some(entry) = self.history.pop_redo() {
1240 let transaction = entry.transaction.clone();
1241 let transaction_id = transaction.id;
1242 let op = self.undo_or_redo(transaction).unwrap();
1243 Some((transaction_id, op))
1244 } else {
1245 None
1246 }
1247 }
1248
1249 pub fn redo_to_transaction(&mut self, transaction_id: TransactionId) -> Vec<Operation> {
1250 let transactions = self
1251 .history
1252 .remove_from_redo(transaction_id)
1253 .iter()
1254 .map(|entry| entry.transaction.clone())
1255 .collect::<Vec<_>>();
1256 transactions
1257 .into_iter()
1258 .map(|transaction| self.undo_or_redo(transaction).unwrap())
1259 .collect()
1260 }
1261
1262 fn undo_or_redo(&mut self, transaction: Transaction) -> Result<Operation> {
1263 let mut counts = HashMap::default();
1264 for edit_id in transaction.edit_ids {
1265 counts.insert(edit_id, self.undo_map.undo_count(edit_id) + 1);
1266 }
1267
1268 let undo = UndoOperation {
1269 id: self.local_clock.tick(),
1270 version: self.version(),
1271 counts,
1272 transaction_ranges: transaction.ranges,
1273 transaction_version: transaction.start.clone(),
1274 };
1275 self.apply_undo(&undo)?;
1276 let operation = Operation::Undo {
1277 undo,
1278 lamport_timestamp: self.lamport_clock.tick(),
1279 };
1280 self.snapshot.version.observe(operation.local_timestamp());
1281 self.history.push(operation.clone());
1282 Ok(operation)
1283 }
1284
1285 pub fn push_transaction(&mut self, transaction: Transaction, now: Instant) {
1286 self.history.push_transaction(transaction, now);
1287 self.history.finalize_last_transaction();
1288 }
1289
1290 pub fn subscribe(&mut self) -> Subscription {
1291 self.subscriptions.subscribe()
1292 }
1293
1294 pub fn wait_for_edits(
1295 &mut self,
1296 edit_ids: impl IntoIterator<Item = clock::Local>,
1297 ) -> impl 'static + Future<Output = ()> {
1298 let mut futures = Vec::new();
1299 for edit_id in edit_ids {
1300 if !self.version.observed(edit_id) {
1301 let (tx, rx) = oneshot::channel();
1302 self.edit_id_resolvers.entry(edit_id).or_default().push(tx);
1303 futures.push(rx);
1304 }
1305 }
1306
1307 async move {
1308 for mut future in futures {
1309 future.recv().await;
1310 }
1311 }
1312 }
1313
1314 pub fn wait_for_anchors<'a>(
1315 &mut self,
1316 anchors: impl IntoIterator<Item = &'a Anchor>,
1317 ) -> impl 'static + Future<Output = ()> {
1318 let mut futures = Vec::new();
1319 for anchor in anchors {
1320 if !self.version.observed(anchor.timestamp)
1321 && *anchor != Anchor::max()
1322 && *anchor != Anchor::min()
1323 {
1324 let (tx, rx) = oneshot::channel();
1325 self.edit_id_resolvers
1326 .entry(anchor.timestamp)
1327 .or_default()
1328 .push(tx);
1329 futures.push(rx);
1330 }
1331 }
1332
1333 async move {
1334 for mut future in futures {
1335 future.recv().await;
1336 }
1337 }
1338 }
1339
1340 pub fn wait_for_version(&mut self, version: clock::Global) -> impl Future<Output = ()> {
1341 let (tx, mut rx) = barrier::channel();
1342 if !self.snapshot.version.observed_all(&version) {
1343 self.version_barriers.push((version, tx));
1344 }
1345 async move {
1346 rx.recv().await;
1347 }
1348 }
1349
1350 fn resolve_edit(&mut self, edit_id: clock::Local) {
1351 for mut tx in self
1352 .edit_id_resolvers
1353 .remove(&edit_id)
1354 .into_iter()
1355 .flatten()
1356 {
1357 let _ = tx.try_send(());
1358 }
1359 }
1360}
1361
1362#[cfg(any(test, feature = "test-support"))]
1363impl Buffer {
1364 pub fn check_invariants(&self) {
1365 // Ensure every fragment is ordered by locator in the fragment tree and corresponds
1366 // to an insertion fragment in the insertions tree.
1367 let mut prev_fragment_id = Locator::min();
1368 for fragment in self.snapshot.fragments.items(&None) {
1369 assert!(fragment.id > prev_fragment_id);
1370 prev_fragment_id = fragment.id.clone();
1371
1372 let insertion_fragment = self
1373 .snapshot
1374 .insertions
1375 .get(
1376 &InsertionFragmentKey {
1377 timestamp: fragment.insertion_timestamp.local(),
1378 split_offset: fragment.insertion_offset,
1379 },
1380 &(),
1381 )
1382 .unwrap();
1383 assert_eq!(insertion_fragment.fragment_id, fragment.id);
1384 }
1385
1386 let mut cursor = self.snapshot.fragments.cursor::<Option<&Locator>>();
1387 for insertion_fragment in self.snapshot.insertions.cursor::<()>() {
1388 cursor.seek(&Some(&insertion_fragment.fragment_id), Bias::Left, &None);
1389 let fragment = cursor.item().unwrap();
1390 assert_eq!(insertion_fragment.fragment_id, fragment.id);
1391 assert_eq!(insertion_fragment.split_offset, fragment.insertion_offset);
1392 }
1393
1394 let fragment_summary = self.snapshot.fragments.summary();
1395 assert_eq!(
1396 fragment_summary.text.visible,
1397 self.snapshot.visible_text.len()
1398 );
1399 assert_eq!(
1400 fragment_summary.text.deleted,
1401 self.snapshot.deleted_text.len()
1402 );
1403 }
1404
1405 pub fn set_group_interval(&mut self, group_interval: Duration) {
1406 self.history.group_interval = group_interval;
1407 }
1408
1409 pub fn random_byte_range(&self, start_offset: usize, rng: &mut impl rand::Rng) -> Range<usize> {
1410 let end = self.clip_offset(rng.gen_range(start_offset..=self.len()), Bias::Right);
1411 let start = self.clip_offset(rng.gen_range(start_offset..=end), Bias::Right);
1412 start..end
1413 }
1414
1415 pub fn randomly_edit<T>(
1416 &mut self,
1417 rng: &mut T,
1418 old_range_count: usize,
1419 ) -> (Vec<Range<usize>>, String, Operation)
1420 where
1421 T: rand::Rng,
1422 {
1423 let mut old_ranges: Vec<Range<usize>> = Vec::new();
1424 for _ in 0..old_range_count {
1425 let last_end = old_ranges.last().map_or(0, |last_range| last_range.end + 1);
1426 if last_end > self.len() {
1427 break;
1428 }
1429 old_ranges.push(self.random_byte_range(last_end, rng));
1430 }
1431 let new_text_len = rng.gen_range(0..10);
1432 let new_text: String = crate::random_char_iter::RandomCharIter::new(&mut *rng)
1433 .take(new_text_len)
1434 .collect();
1435 log::info!(
1436 "mutating buffer {} at {:?}: {:?}",
1437 self.replica_id,
1438 old_ranges,
1439 new_text
1440 );
1441 let op = self.edit(old_ranges.iter().cloned(), new_text.as_str());
1442 (old_ranges, new_text, op)
1443 }
1444
1445 pub fn randomly_undo_redo(&mut self, rng: &mut impl rand::Rng) -> Vec<Operation> {
1446 use rand::prelude::*;
1447
1448 let mut ops = Vec::new();
1449 for _ in 0..rng.gen_range(1..=5) {
1450 if let Some(entry) = self.history.undo_stack.choose(rng) {
1451 let transaction = entry.transaction.clone();
1452 log::info!(
1453 "undoing buffer {} transaction {:?}",
1454 self.replica_id,
1455 transaction
1456 );
1457 ops.push(self.undo_or_redo(transaction).unwrap());
1458 }
1459 }
1460 ops
1461 }
1462}
1463
1464impl Deref for Buffer {
1465 type Target = BufferSnapshot;
1466
1467 fn deref(&self) -> &Self::Target {
1468 &self.snapshot
1469 }
1470}
1471
1472impl BufferSnapshot {
1473 pub fn as_rope(&self) -> &Rope {
1474 &self.visible_text
1475 }
1476
1477 pub fn replica_id(&self) -> ReplicaId {
1478 self.replica_id
1479 }
1480
1481 pub fn row_count(&self) -> u32 {
1482 self.max_point().row + 1
1483 }
1484
1485 pub fn len(&self) -> usize {
1486 self.visible_text.len()
1487 }
1488
1489 pub fn chars(&self) -> impl Iterator<Item = char> + '_ {
1490 self.chars_at(0)
1491 }
1492
1493 pub fn chars_for_range<T: ToOffset>(&self, range: Range<T>) -> impl Iterator<Item = char> + '_ {
1494 self.text_for_range(range).flat_map(str::chars)
1495 }
1496
1497 pub fn contains_str_at<T>(&self, position: T, needle: &str) -> bool
1498 where
1499 T: ToOffset,
1500 {
1501 let position = position.to_offset(self);
1502 position == self.clip_offset(position, Bias::Left)
1503 && self
1504 .bytes_in_range(position..self.len())
1505 .flatten()
1506 .copied()
1507 .take(needle.len())
1508 .eq(needle.bytes())
1509 }
1510
1511 pub fn text(&self) -> String {
1512 self.visible_text.to_string()
1513 }
1514
1515 pub fn deleted_text(&self) -> String {
1516 self.deleted_text.to_string()
1517 }
1518
1519 pub fn fragments(&self) -> impl Iterator<Item = &Fragment> {
1520 self.fragments.iter()
1521 }
1522
1523 pub fn text_summary(&self) -> TextSummary {
1524 self.visible_text.summary()
1525 }
1526
1527 pub fn max_point(&self) -> Point {
1528 self.visible_text.max_point()
1529 }
1530
1531 pub fn max_point_utf16(&self) -> PointUtf16 {
1532 self.visible_text.max_point_utf16()
1533 }
1534
1535 pub fn point_to_offset(&self, point: Point) -> usize {
1536 self.visible_text.point_to_offset(point)
1537 }
1538
1539 pub fn point_utf16_to_offset(&self, point: PointUtf16) -> usize {
1540 self.visible_text.point_utf16_to_offset(point)
1541 }
1542
1543 pub fn point_utf16_to_point(&self, point: PointUtf16) -> Point {
1544 self.visible_text.point_utf16_to_point(point)
1545 }
1546
1547 pub fn offset_to_point(&self, offset: usize) -> Point {
1548 self.visible_text.offset_to_point(offset)
1549 }
1550
1551 pub fn offset_to_point_utf16(&self, offset: usize) -> PointUtf16 {
1552 self.visible_text.offset_to_point_utf16(offset)
1553 }
1554
1555 pub fn point_to_point_utf16(&self, point: Point) -> PointUtf16 {
1556 self.visible_text.point_to_point_utf16(point)
1557 }
1558
1559 pub fn version(&self) -> &clock::Global {
1560 &self.version
1561 }
1562
1563 pub fn chars_at<'a, T: ToOffset>(&'a self, position: T) -> impl Iterator<Item = char> + 'a {
1564 let offset = position.to_offset(self);
1565 self.visible_text.chars_at(offset)
1566 }
1567
1568 pub fn reversed_chars_at<'a, T: ToOffset>(
1569 &'a self,
1570 position: T,
1571 ) -> impl Iterator<Item = char> + 'a {
1572 let offset = position.to_offset(self);
1573 self.visible_text.reversed_chars_at(offset)
1574 }
1575
1576 pub fn reversed_chunks_in_range<T: ToOffset>(&self, range: Range<T>) -> rope::Chunks {
1577 let range = range.start.to_offset(self)..range.end.to_offset(self);
1578 self.visible_text.reversed_chunks_in_range(range)
1579 }
1580
1581 pub fn bytes_in_range<'a, T: ToOffset>(&'a self, range: Range<T>) -> rope::Bytes<'a> {
1582 let start = range.start.to_offset(self);
1583 let end = range.end.to_offset(self);
1584 self.visible_text.bytes_in_range(start..end)
1585 }
1586
1587 pub fn text_for_range<'a, T: ToOffset>(&'a self, range: Range<T>) -> Chunks<'a> {
1588 let start = range.start.to_offset(self);
1589 let end = range.end.to_offset(self);
1590 self.visible_text.chunks_in_range(start..end)
1591 }
1592
1593 pub fn line_len(&self, row: u32) -> u32 {
1594 let row_start_offset = Point::new(row, 0).to_offset(self);
1595 let row_end_offset = if row >= self.max_point().row {
1596 self.len()
1597 } else {
1598 Point::new(row + 1, 0).to_offset(self) - 1
1599 };
1600 (row_end_offset - row_start_offset) as u32
1601 }
1602
1603 pub fn is_line_blank(&self, row: u32) -> bool {
1604 self.text_for_range(Point::new(row, 0)..Point::new(row, self.line_len(row)))
1605 .all(|chunk| chunk.matches(|c: char| !c.is_whitespace()).next().is_none())
1606 }
1607
1608 pub fn indent_column_for_line(&self, row: u32) -> u32 {
1609 let mut result = 0;
1610 for c in self.chars_at(Point::new(row, 0)) {
1611 if c == ' ' {
1612 result += 1;
1613 } else {
1614 break;
1615 }
1616 }
1617 result
1618 }
1619
1620 pub fn text_summary_for_range<'a, D, O: ToOffset>(&'a self, range: Range<O>) -> D
1621 where
1622 D: TextDimension,
1623 {
1624 self.visible_text
1625 .cursor(range.start.to_offset(self))
1626 .summary(range.end.to_offset(self))
1627 }
1628
1629 pub fn summaries_for_anchors<'a, D, A>(&'a self, anchors: A) -> impl 'a + Iterator<Item = D>
1630 where
1631 D: 'a + TextDimension,
1632 A: 'a + IntoIterator<Item = &'a Anchor>,
1633 {
1634 let anchors = anchors.into_iter();
1635 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1636 let mut fragment_cursor = self.fragments.cursor::<(Option<&Locator>, usize)>();
1637 let mut text_cursor = self.visible_text.cursor(0);
1638 let mut position = D::default();
1639
1640 anchors.map(move |anchor| {
1641 if *anchor == Anchor::min() {
1642 return D::default();
1643 } else if *anchor == Anchor::max() {
1644 return D::from_text_summary(&self.visible_text.summary());
1645 }
1646
1647 let anchor_key = InsertionFragmentKey {
1648 timestamp: anchor.timestamp,
1649 split_offset: anchor.offset,
1650 };
1651 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1652 if let Some(insertion) = insertion_cursor.item() {
1653 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1654 if comparison == Ordering::Greater
1655 || (anchor.bias == Bias::Left
1656 && comparison == Ordering::Equal
1657 && anchor.offset > 0)
1658 {
1659 insertion_cursor.prev(&());
1660 }
1661 } else {
1662 insertion_cursor.prev(&());
1663 }
1664 let insertion = insertion_cursor.item().expect("invalid insertion");
1665 assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1666
1667 fragment_cursor.seek_forward(&Some(&insertion.fragment_id), Bias::Left, &None);
1668 let fragment = fragment_cursor.item().unwrap();
1669 let mut fragment_offset = fragment_cursor.start().1;
1670 if fragment.visible {
1671 fragment_offset += anchor.offset - insertion.split_offset;
1672 }
1673
1674 position.add_assign(&text_cursor.summary(fragment_offset));
1675 position.clone()
1676 })
1677 }
1678
1679 fn summary_for_anchor<'a, D>(&'a self, anchor: &Anchor) -> D
1680 where
1681 D: TextDimension,
1682 {
1683 if *anchor == Anchor::min() {
1684 D::default()
1685 } else if *anchor == Anchor::max() {
1686 D::from_text_summary(&self.visible_text.summary())
1687 } else {
1688 let anchor_key = InsertionFragmentKey {
1689 timestamp: anchor.timestamp,
1690 split_offset: anchor.offset,
1691 };
1692 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1693 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1694 if let Some(insertion) = insertion_cursor.item() {
1695 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1696 if comparison == Ordering::Greater
1697 || (anchor.bias == Bias::Left
1698 && comparison == Ordering::Equal
1699 && anchor.offset > 0)
1700 {
1701 insertion_cursor.prev(&());
1702 }
1703 } else {
1704 insertion_cursor.prev(&());
1705 }
1706 let insertion = insertion_cursor.item().expect("invalid insertion");
1707 assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1708
1709 let mut fragment_cursor = self.fragments.cursor::<(Option<&Locator>, usize)>();
1710 fragment_cursor.seek(&Some(&insertion.fragment_id), Bias::Left, &None);
1711 let fragment = fragment_cursor.item().unwrap();
1712 let mut fragment_offset = fragment_cursor.start().1;
1713 if fragment.visible {
1714 fragment_offset += anchor.offset - insertion.split_offset;
1715 }
1716 self.text_summary_for_range(0..fragment_offset)
1717 }
1718 }
1719
1720 fn fragment_id_for_anchor(&self, anchor: &Anchor) -> &Locator {
1721 if *anchor == Anchor::min() {
1722 &locator::MIN
1723 } else if *anchor == Anchor::max() {
1724 &locator::MAX
1725 } else {
1726 let anchor_key = InsertionFragmentKey {
1727 timestamp: anchor.timestamp,
1728 split_offset: anchor.offset,
1729 };
1730 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1731 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1732 if let Some(insertion) = insertion_cursor.item() {
1733 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1734 if comparison == Ordering::Greater
1735 || (anchor.bias == Bias::Left
1736 && comparison == Ordering::Equal
1737 && anchor.offset > 0)
1738 {
1739 insertion_cursor.prev(&());
1740 }
1741 } else {
1742 insertion_cursor.prev(&());
1743 }
1744 let insertion = insertion_cursor.item().expect("invalid insertion");
1745 debug_assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1746 &insertion.fragment_id
1747 }
1748 }
1749
1750 pub fn anchor_before<T: ToOffset>(&self, position: T) -> Anchor {
1751 self.anchor_at(position, Bias::Left)
1752 }
1753
1754 pub fn anchor_after<T: ToOffset>(&self, position: T) -> Anchor {
1755 self.anchor_at(position, Bias::Right)
1756 }
1757
1758 pub fn anchor_at<T: ToOffset>(&self, position: T, bias: Bias) -> Anchor {
1759 let offset = position.to_offset(self);
1760 if bias == Bias::Left && offset == 0 {
1761 Anchor::min()
1762 } else if bias == Bias::Right && offset == self.len() {
1763 Anchor::max()
1764 } else {
1765 let mut fragment_cursor = self.fragments.cursor::<usize>();
1766 fragment_cursor.seek(&offset, bias, &None);
1767 let fragment = fragment_cursor.item().unwrap();
1768 let overshoot = offset - *fragment_cursor.start();
1769 Anchor {
1770 timestamp: fragment.insertion_timestamp.local(),
1771 offset: fragment.insertion_offset + overshoot,
1772 bias,
1773 }
1774 }
1775 }
1776
1777 pub fn can_resolve(&self, anchor: &Anchor) -> bool {
1778 *anchor == Anchor::min()
1779 || *anchor == Anchor::max()
1780 || self.version.observed(anchor.timestamp)
1781 }
1782
1783 pub fn clip_offset(&self, offset: usize, bias: Bias) -> usize {
1784 self.visible_text.clip_offset(offset, bias)
1785 }
1786
1787 pub fn clip_point(&self, point: Point, bias: Bias) -> Point {
1788 self.visible_text.clip_point(point, bias)
1789 }
1790
1791 pub fn clip_point_utf16(&self, point: PointUtf16, bias: Bias) -> PointUtf16 {
1792 self.visible_text.clip_point_utf16(point, bias)
1793 }
1794
1795 pub fn edits_since<'a, D>(
1796 &'a self,
1797 since: &'a clock::Global,
1798 ) -> impl 'a + Iterator<Item = Edit<D>>
1799 where
1800 D: TextDimension + Ord,
1801 {
1802 self.edits_since_in_range(since, Anchor::min()..Anchor::max())
1803 }
1804
1805 pub fn edited_ranges_for_transaction<'a, D>(
1806 &'a self,
1807 transaction: &'a Transaction,
1808 ) -> impl 'a + Iterator<Item = Range<D>>
1809 where
1810 D: TextDimension,
1811 {
1812 let mut cursor = self.fragments.cursor::<(VersionedFullOffset, usize)>();
1813 let mut rope_cursor = self.visible_text.cursor(0);
1814 let cx = Some(transaction.end.clone());
1815 let mut position = D::default();
1816 transaction.ranges.iter().map(move |range| {
1817 cursor.seek_forward(&VersionedFullOffset::Offset(range.start), Bias::Right, &cx);
1818 let mut start_offset = cursor.start().1;
1819 if cursor
1820 .item()
1821 .map_or(false, |fragment| fragment.is_visible(&self.undo_map))
1822 {
1823 start_offset += range.start - cursor.start().0.full_offset()
1824 }
1825 position.add_assign(&rope_cursor.summary(start_offset));
1826 let start = position.clone();
1827
1828 cursor.seek_forward(&VersionedFullOffset::Offset(range.end), Bias::Left, &cx);
1829 let mut end_offset = cursor.start().1;
1830 if cursor
1831 .item()
1832 .map_or(false, |fragment| fragment.is_visible(&self.undo_map))
1833 {
1834 end_offset += range.end - cursor.start().0.full_offset();
1835 }
1836 position.add_assign(&rope_cursor.summary(end_offset));
1837 start..position.clone()
1838 })
1839 }
1840
1841 pub fn edits_since_in_range<'a, D>(
1842 &'a self,
1843 since: &'a clock::Global,
1844 range: Range<Anchor>,
1845 ) -> impl 'a + Iterator<Item = Edit<D>>
1846 where
1847 D: TextDimension + Ord,
1848 {
1849 let fragments_cursor = if *since == self.version {
1850 None
1851 } else {
1852 Some(self.fragments.filter(
1853 move |summary| !since.observed_all(&summary.max_version),
1854 &None,
1855 ))
1856 };
1857 let mut cursor = self
1858 .fragments
1859 .cursor::<(Option<&Locator>, FragmentTextSummary)>();
1860
1861 let start_fragment_id = self.fragment_id_for_anchor(&range.start);
1862 cursor.seek(&Some(start_fragment_id), Bias::Left, &None);
1863 let mut visible_start = cursor.start().1.visible;
1864 let mut deleted_start = cursor.start().1.deleted;
1865 if let Some(fragment) = cursor.item() {
1866 let overshoot = range.start.offset - fragment.insertion_offset;
1867 if fragment.visible {
1868 visible_start += overshoot;
1869 } else {
1870 deleted_start += overshoot;
1871 }
1872 }
1873 let end_fragment_id = self.fragment_id_for_anchor(&range.end);
1874
1875 Edits {
1876 visible_cursor: self.visible_text.cursor(visible_start),
1877 deleted_cursor: self.deleted_text.cursor(deleted_start),
1878 fragments_cursor,
1879 undos: &self.undo_map,
1880 since,
1881 old_end: Default::default(),
1882 new_end: Default::default(),
1883 range: (start_fragment_id, range.start.offset)..(end_fragment_id, range.end.offset),
1884 }
1885 }
1886}
1887
1888struct RopeBuilder<'a> {
1889 old_visible_cursor: rope::Cursor<'a>,
1890 old_deleted_cursor: rope::Cursor<'a>,
1891 new_visible: Rope,
1892 new_deleted: Rope,
1893}
1894
1895impl<'a> RopeBuilder<'a> {
1896 fn new(old_visible_cursor: rope::Cursor<'a>, old_deleted_cursor: rope::Cursor<'a>) -> Self {
1897 Self {
1898 old_visible_cursor,
1899 old_deleted_cursor,
1900 new_visible: Rope::new(),
1901 new_deleted: Rope::new(),
1902 }
1903 }
1904
1905 fn push_tree(&mut self, len: FragmentTextSummary) {
1906 self.push(len.visible, true, true);
1907 self.push(len.deleted, false, false);
1908 }
1909
1910 fn push_fragment(&mut self, fragment: &Fragment, was_visible: bool) {
1911 debug_assert!(fragment.len > 0);
1912 self.push(fragment.len, was_visible, fragment.visible)
1913 }
1914
1915 fn push(&mut self, len: usize, was_visible: bool, is_visible: bool) {
1916 let text = if was_visible {
1917 self.old_visible_cursor
1918 .slice(self.old_visible_cursor.offset() + len)
1919 } else {
1920 self.old_deleted_cursor
1921 .slice(self.old_deleted_cursor.offset() + len)
1922 };
1923 if is_visible {
1924 self.new_visible.append(text);
1925 } else {
1926 self.new_deleted.append(text);
1927 }
1928 }
1929
1930 fn push_str(&mut self, text: &str) {
1931 self.new_visible.push(text);
1932 }
1933
1934 fn finish(mut self) -> (Rope, Rope) {
1935 self.new_visible.append(self.old_visible_cursor.suffix());
1936 self.new_deleted.append(self.old_deleted_cursor.suffix());
1937 (self.new_visible, self.new_deleted)
1938 }
1939}
1940
1941impl<'a, D: TextDimension + Ord, F: FnMut(&FragmentSummary) -> bool> Iterator for Edits<'a, D, F> {
1942 type Item = Edit<D>;
1943
1944 fn next(&mut self) -> Option<Self::Item> {
1945 let mut pending_edit: Option<Edit<D>> = None;
1946 let cursor = self.fragments_cursor.as_mut()?;
1947
1948 while let Some(fragment) = cursor.item() {
1949 if fragment.id < *self.range.start.0 {
1950 cursor.next(&None);
1951 continue;
1952 } else if fragment.id > *self.range.end.0 {
1953 break;
1954 }
1955
1956 if cursor.start().visible > self.visible_cursor.offset() {
1957 let summary = self.visible_cursor.summary(cursor.start().visible);
1958 self.old_end.add_assign(&summary);
1959 self.new_end.add_assign(&summary);
1960 }
1961
1962 if pending_edit
1963 .as_ref()
1964 .map_or(false, |change| change.new.end < self.new_end)
1965 {
1966 break;
1967 }
1968
1969 if !fragment.was_visible(&self.since, &self.undos) && fragment.visible {
1970 let mut visible_end = cursor.end(&None).visible;
1971 if fragment.id == *self.range.end.0 {
1972 visible_end = cmp::min(
1973 visible_end,
1974 cursor.start().visible + (self.range.end.1 - fragment.insertion_offset),
1975 );
1976 }
1977
1978 let fragment_summary = self.visible_cursor.summary(visible_end);
1979 let mut new_end = self.new_end.clone();
1980 new_end.add_assign(&fragment_summary);
1981 if let Some(pending_edit) = pending_edit.as_mut() {
1982 pending_edit.new.end = new_end.clone();
1983 } else {
1984 pending_edit = Some(Edit {
1985 old: self.old_end.clone()..self.old_end.clone(),
1986 new: self.new_end.clone()..new_end.clone(),
1987 });
1988 }
1989
1990 self.new_end = new_end;
1991 } else if fragment.was_visible(&self.since, &self.undos) && !fragment.visible {
1992 let mut deleted_end = cursor.end(&None).deleted;
1993 if fragment.id == *self.range.end.0 {
1994 deleted_end = cmp::min(
1995 deleted_end,
1996 cursor.start().deleted + (self.range.end.1 - fragment.insertion_offset),
1997 );
1998 }
1999
2000 if cursor.start().deleted > self.deleted_cursor.offset() {
2001 self.deleted_cursor.seek_forward(cursor.start().deleted);
2002 }
2003 let fragment_summary = self.deleted_cursor.summary(deleted_end);
2004 let mut old_end = self.old_end.clone();
2005 old_end.add_assign(&fragment_summary);
2006 if let Some(pending_edit) = pending_edit.as_mut() {
2007 pending_edit.old.end = old_end.clone();
2008 } else {
2009 pending_edit = Some(Edit {
2010 old: self.old_end.clone()..old_end.clone(),
2011 new: self.new_end.clone()..self.new_end.clone(),
2012 });
2013 }
2014
2015 self.old_end = old_end;
2016 }
2017
2018 cursor.next(&None);
2019 }
2020
2021 pending_edit
2022 }
2023}
2024
2025impl Fragment {
2026 fn is_visible(&self, undos: &UndoMap) -> bool {
2027 !undos.is_undone(self.insertion_timestamp.local())
2028 && self.deletions.iter().all(|d| undos.is_undone(*d))
2029 }
2030
2031 fn was_visible(&self, version: &clock::Global, undos: &UndoMap) -> bool {
2032 (version.observed(self.insertion_timestamp.local())
2033 && !undos.was_undone(self.insertion_timestamp.local(), version))
2034 && self
2035 .deletions
2036 .iter()
2037 .all(|d| !version.observed(*d) || undos.was_undone(*d, version))
2038 }
2039}
2040
2041impl sum_tree::Item for Fragment {
2042 type Summary = FragmentSummary;
2043
2044 fn summary(&self) -> Self::Summary {
2045 let mut max_version = clock::Global::new();
2046 max_version.observe(self.insertion_timestamp.local());
2047 for deletion in &self.deletions {
2048 max_version.observe(*deletion);
2049 }
2050 max_version.join(&self.max_undos);
2051
2052 let mut min_insertion_version = clock::Global::new();
2053 min_insertion_version.observe(self.insertion_timestamp.local());
2054 let max_insertion_version = min_insertion_version.clone();
2055 if self.visible {
2056 FragmentSummary {
2057 max_id: self.id.clone(),
2058 text: FragmentTextSummary {
2059 visible: self.len,
2060 deleted: 0,
2061 },
2062 max_version,
2063 min_insertion_version,
2064 max_insertion_version,
2065 }
2066 } else {
2067 FragmentSummary {
2068 max_id: self.id.clone(),
2069 text: FragmentTextSummary {
2070 visible: 0,
2071 deleted: self.len,
2072 },
2073 max_version,
2074 min_insertion_version,
2075 max_insertion_version,
2076 }
2077 }
2078 }
2079}
2080
2081impl sum_tree::Summary for FragmentSummary {
2082 type Context = Option<clock::Global>;
2083
2084 fn add_summary(&mut self, other: &Self, _: &Self::Context) {
2085 self.max_id.assign(&other.max_id);
2086 self.text.visible += &other.text.visible;
2087 self.text.deleted += &other.text.deleted;
2088 self.max_version.join(&other.max_version);
2089 self.min_insertion_version
2090 .meet(&other.min_insertion_version);
2091 self.max_insertion_version
2092 .join(&other.max_insertion_version);
2093 }
2094}
2095
2096impl Default for FragmentSummary {
2097 fn default() -> Self {
2098 FragmentSummary {
2099 max_id: Locator::min(),
2100 text: FragmentTextSummary::default(),
2101 max_version: clock::Global::new(),
2102 min_insertion_version: clock::Global::new(),
2103 max_insertion_version: clock::Global::new(),
2104 }
2105 }
2106}
2107
2108impl sum_tree::Item for InsertionFragment {
2109 type Summary = InsertionFragmentKey;
2110
2111 fn summary(&self) -> Self::Summary {
2112 InsertionFragmentKey {
2113 timestamp: self.timestamp,
2114 split_offset: self.split_offset,
2115 }
2116 }
2117}
2118
2119impl sum_tree::KeyedItem for InsertionFragment {
2120 type Key = InsertionFragmentKey;
2121
2122 fn key(&self) -> Self::Key {
2123 sum_tree::Item::summary(self)
2124 }
2125}
2126
2127impl InsertionFragment {
2128 fn new(fragment: &Fragment) -> Self {
2129 Self {
2130 timestamp: fragment.insertion_timestamp.local(),
2131 split_offset: fragment.insertion_offset,
2132 fragment_id: fragment.id.clone(),
2133 }
2134 }
2135
2136 fn insert_new(fragment: &Fragment) -> sum_tree::Edit<Self> {
2137 sum_tree::Edit::Insert(Self::new(fragment))
2138 }
2139}
2140
2141impl sum_tree::Summary for InsertionFragmentKey {
2142 type Context = ();
2143
2144 fn add_summary(&mut self, summary: &Self, _: &()) {
2145 *self = *summary;
2146 }
2147}
2148
2149#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
2150pub struct FullOffset(pub usize);
2151
2152impl ops::AddAssign<usize> for FullOffset {
2153 fn add_assign(&mut self, rhs: usize) {
2154 self.0 += rhs;
2155 }
2156}
2157
2158impl ops::Add<usize> for FullOffset {
2159 type Output = Self;
2160
2161 fn add(mut self, rhs: usize) -> Self::Output {
2162 self += rhs;
2163 self
2164 }
2165}
2166
2167impl ops::Sub for FullOffset {
2168 type Output = usize;
2169
2170 fn sub(self, rhs: Self) -> Self::Output {
2171 self.0 - rhs.0
2172 }
2173}
2174
2175impl<'a> sum_tree::Dimension<'a, FragmentSummary> for usize {
2176 fn add_summary(&mut self, summary: &FragmentSummary, _: &Option<clock::Global>) {
2177 *self += summary.text.visible;
2178 }
2179}
2180
2181impl<'a> sum_tree::Dimension<'a, FragmentSummary> for FullOffset {
2182 fn add_summary(&mut self, summary: &FragmentSummary, _: &Option<clock::Global>) {
2183 self.0 += summary.text.visible + summary.text.deleted;
2184 }
2185}
2186
2187impl<'a> sum_tree::Dimension<'a, FragmentSummary> for Option<&'a Locator> {
2188 fn add_summary(&mut self, summary: &'a FragmentSummary, _: &Option<clock::Global>) {
2189 *self = Some(&summary.max_id);
2190 }
2191}
2192
2193impl<'a> sum_tree::SeekTarget<'a, FragmentSummary, FragmentTextSummary> for usize {
2194 fn cmp(
2195 &self,
2196 cursor_location: &FragmentTextSummary,
2197 _: &Option<clock::Global>,
2198 ) -> cmp::Ordering {
2199 Ord::cmp(self, &cursor_location.visible)
2200 }
2201}
2202
2203#[derive(Copy, Clone, Debug, Eq, PartialEq)]
2204enum VersionedFullOffset {
2205 Offset(FullOffset),
2206 Invalid,
2207}
2208
2209impl VersionedFullOffset {
2210 fn full_offset(&self) -> FullOffset {
2211 if let Self::Offset(position) = self {
2212 *position
2213 } else {
2214 panic!("invalid version")
2215 }
2216 }
2217}
2218
2219impl Default for VersionedFullOffset {
2220 fn default() -> Self {
2221 Self::Offset(Default::default())
2222 }
2223}
2224
2225impl<'a> sum_tree::Dimension<'a, FragmentSummary> for VersionedFullOffset {
2226 fn add_summary(&mut self, summary: &'a FragmentSummary, cx: &Option<clock::Global>) {
2227 if let Self::Offset(offset) = self {
2228 let version = cx.as_ref().unwrap();
2229 if version.observed_all(&summary.max_insertion_version) {
2230 *offset += summary.text.visible + summary.text.deleted;
2231 } else if version.observed_any(&summary.min_insertion_version) {
2232 *self = Self::Invalid;
2233 }
2234 }
2235 }
2236}
2237
2238impl<'a> sum_tree::SeekTarget<'a, FragmentSummary, Self> for VersionedFullOffset {
2239 fn cmp(&self, cursor_position: &Self, _: &Option<clock::Global>) -> cmp::Ordering {
2240 match (self, cursor_position) {
2241 (Self::Offset(a), Self::Offset(b)) => Ord::cmp(a, b),
2242 (Self::Offset(_), Self::Invalid) => cmp::Ordering::Less,
2243 (Self::Invalid, _) => unreachable!(),
2244 }
2245 }
2246}
2247
2248impl Operation {
2249 fn replica_id(&self) -> ReplicaId {
2250 operation_queue::Operation::lamport_timestamp(self).replica_id
2251 }
2252
2253 pub fn local_timestamp(&self) -> clock::Local {
2254 match self {
2255 Operation::Edit(edit) => edit.timestamp.local(),
2256 Operation::Undo { undo, .. } => undo.id,
2257 }
2258 }
2259
2260 pub fn as_edit(&self) -> Option<&EditOperation> {
2261 match self {
2262 Operation::Edit(edit) => Some(edit),
2263 _ => None,
2264 }
2265 }
2266
2267 pub fn is_edit(&self) -> bool {
2268 match self {
2269 Operation::Edit { .. } => true,
2270 _ => false,
2271 }
2272 }
2273}
2274
2275impl operation_queue::Operation for Operation {
2276 fn lamport_timestamp(&self) -> clock::Lamport {
2277 match self {
2278 Operation::Edit(edit) => edit.timestamp.lamport(),
2279 Operation::Undo {
2280 lamport_timestamp, ..
2281 } => *lamport_timestamp,
2282 }
2283 }
2284}
2285
2286pub trait ToOffset {
2287 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize;
2288}
2289
2290impl ToOffset for Point {
2291 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2292 snapshot.point_to_offset(*self)
2293 }
2294}
2295
2296impl ToOffset for PointUtf16 {
2297 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2298 snapshot.point_utf16_to_offset(*self)
2299 }
2300}
2301
2302impl ToOffset for usize {
2303 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2304 assert!(*self <= snapshot.len(), "offset is out of range");
2305 *self
2306 }
2307}
2308
2309impl ToOffset for Anchor {
2310 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2311 snapshot.summary_for_anchor(self)
2312 }
2313}
2314
2315impl<'a, T: ToOffset> ToOffset for &'a T {
2316 fn to_offset(&self, content: &BufferSnapshot) -> usize {
2317 (*self).to_offset(content)
2318 }
2319}
2320
2321pub trait ToPoint {
2322 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point;
2323}
2324
2325impl ToPoint for Anchor {
2326 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2327 snapshot.summary_for_anchor(self)
2328 }
2329}
2330
2331impl ToPoint for usize {
2332 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2333 snapshot.offset_to_point(*self)
2334 }
2335}
2336
2337impl ToPoint for PointUtf16 {
2338 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2339 snapshot.point_utf16_to_point(*self)
2340 }
2341}
2342
2343impl ToPoint for Point {
2344 fn to_point<'a>(&self, _: &BufferSnapshot) -> Point {
2345 *self
2346 }
2347}
2348
2349pub trait ToPointUtf16 {
2350 fn to_point_utf16<'a>(&self, snapshot: &BufferSnapshot) -> PointUtf16;
2351}
2352
2353impl ToPointUtf16 for Anchor {
2354 fn to_point_utf16<'a>(&self, snapshot: &BufferSnapshot) -> PointUtf16 {
2355 snapshot.summary_for_anchor(self)
2356 }
2357}
2358
2359impl ToPointUtf16 for usize {
2360 fn to_point_utf16<'a>(&self, snapshot: &BufferSnapshot) -> PointUtf16 {
2361 snapshot.offset_to_point_utf16(*self)
2362 }
2363}
2364
2365impl ToPointUtf16 for PointUtf16 {
2366 fn to_point_utf16<'a>(&self, _: &BufferSnapshot) -> PointUtf16 {
2367 *self
2368 }
2369}
2370
2371impl ToPointUtf16 for Point {
2372 fn to_point_utf16<'a>(&self, snapshot: &BufferSnapshot) -> PointUtf16 {
2373 snapshot.point_to_point_utf16(*self)
2374 }
2375}
2376
2377pub trait Clip {
2378 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self;
2379}
2380
2381impl Clip for usize {
2382 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2383 snapshot.clip_offset(*self, bias)
2384 }
2385}
2386
2387impl Clip for Point {
2388 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2389 snapshot.clip_point(*self, bias)
2390 }
2391}
2392
2393impl Clip for PointUtf16 {
2394 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2395 snapshot.clip_point_utf16(*self, bias)
2396 }
2397}
2398
2399pub trait FromAnchor {
2400 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self;
2401}
2402
2403impl FromAnchor for Point {
2404 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2405 snapshot.summary_for_anchor(anchor)
2406 }
2407}
2408
2409impl FromAnchor for PointUtf16 {
2410 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2411 snapshot.summary_for_anchor(anchor)
2412 }
2413}
2414
2415impl FromAnchor for usize {
2416 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2417 snapshot.summary_for_anchor(anchor)
2418 }
2419}